About half of women who undergo mammograms have breast tissue that radiologists term “dense fibroglandular.” A state law that takes effect Jan. 19 requires mammography centers to notify women who have dense breasts, telling them that having dense breasts may put them at increased risk for breast cancer and that cancers are difficult to spot in dense tissue on a mammogram.

The letters may frighten some women, who will be advised to talk to their primary care providers about whether additional imaging is appropriate.

Upstate now offers 3D mammography, called tomosynthesis, which may appeal especially to women with dense breasts. Taken just like a regular mammogram, tomosynthesis takes several 1-millimeter image slices of the breast, giving radiologists a better look.

“With this technology, dense breasts can be evaluated,” says Deepa Masrani MD, section chief of women’s imaging at Upstate. She is pleased with the accuracy, but she admits, “it’s not 100 percent. It’s still a mammogram.”

That means a woman with dense breasts may still have to consider additional imaging, depending on her lifetime risk of developing breast cancer, Masrani says. One’s lifetime risk can be calculated with assistance from the primary care provider and is based on a number of factors including family history of the disease.

Women with 20 percent or greater lifetime risk are advised to undergo a bilateral breast MRI. Those with less than a 20 percent lifetime risk who, nonetheless, remain apprehensive are advised to undergo screening breast ultrasound.

“The downfall to (additional testing) is that there are a lot of false positives,” says Masrani, which means some women may undergo procedures such as biopsy that turn out to be unnecessary.

A woman cannot tell by touch whether she has dense breasts. And, breast density can change over time, influenced by her weight, age, hormone levels and alcohol usage. Regardless of breast density, experts stress that mammograms are still the best screening tool against breast cancer, and they are recommended annually for women 40 and older.

Katherine Willer MD, an Upstate radiologist specializing in breast imaging, says patients can help get the most accurate mammogram by going to the same mammography center, or making sure they bring previous images when they go to a new center. Radiologists like to have older images to compare with the newer, to help spot changes.

Willer also supports patients doing their own monthly breast exams. “I’ve seen a number of patients who have palpated their own cancer.”’